To add a connection to areas made by another author, it's required to personally contact them and get their permission to add said connection. To make matters more expeditious, red construction signs and barriers were added to the game, which indicate that the place where said objects are located is open for any other author to add new connections.
The following page lists areas which have the aforementioned entrances.
Pages in category "Open for Cross-Author Connections"
The following 56 pages are in this category, out of 56 total.